Digital Isolator

Abstract

To provide a digital isolator capable of improving an insulation breakdown resistance.SOLUTION: A digital isolator according to an embodiment, comprises: a first electrode; a first insulation part; a second electrode; a second insulation part; and a first dielectric part. The first insulation part is provided under the first electrode. The second electrode is provided under the first insulation part. The second insulation part is provided to a circumference of the first electrode along a first surface vertical to a first direction directed to the first electrode from the second electrode. The first dielectric part is provided between the first electrode and the second insulation part in a second direction along the first surface, and is contacted to the first electrode. A relative dielectric constant of the first dielectric part is higher than the relative dielectric constant of the first insulation part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a digital isolator. [Background technology]

[0002] Digital isolators transmit signals by utilizing changes in a magnetic or electric field while blocking current. It is desirable for these digital isolators to have high resistance to dielectric breakdown. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2017-538277 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a digital isolator capable of improving dielectric breakdown resistance. [Means for solving the problem]

[0005] A digital isolator according to an embodiment includes a first electrode, a first insulating portion, a second electrode, a second insulating portion, and a first dielectric portion. The first insulating portion is provided below the first electrode. The second electrode is provided below the first insulating portion. The second insulating portion is provided around the first electrode along a first surface perpendicular to a first direction from the second electrode to the first electrode. The first dielectric portion is provided between the first electrode and the second insulating portion in a second direction along the first surface, and is in contact with the first electrode. The relative dielectric constant of the first dielectric portion is higher than the relative dielectric constant of the first insulating portion. [Brief description of the drawings]

[0006] [Figure 1]1 is a cross-sectional view illustrating a digital isolator according to a first embodiment. [Diagram 2] FIG. 6 is a cross-sectional view illustrating a digital isolator according to a second embodiment. [Diagram 3] FIG. 11 is a cross-sectional view illustrating a digital isolator according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. In this specification and each drawing, elements similar to those already explained are given the same reference numerals and detailed explanations are omitted as appropriate.

[0008] (First embodiment) FIG. 1 is a cross-sectional view illustrating a digital isolator according to the first embodiment. As shown in FIG. 1, the digital isolator 100 of the first embodiment includes a first electrode 11, a second electrode 12, a first insulating section 21, a second insulating section 22, a third insulating section 23, an upper insulating section 28, a first dielectric section 31, a second dielectric section 32, a first intermediate dielectric section 33, a second intermediate dielectric section 34, insulating layers 41 to 43, and a conductor 50.

[0009] In the description of the embodiment, an XYZ Cartesian coordinate system is used. The direction from the second electrode 12 to the first electrode 11 is defined as the Z direction (first direction). Two directions that are perpendicular to the Z direction and perpendicular to each other are defined as the X direction (second direction) and the Y direction (third direction). For the sake of description, the direction from the second electrode 12 to the first electrode 11 is referred to as "up" and the opposite direction is referred to as "down". These directions are based on the relative positional relationship between the first electrode 11 and the second electrode 12 and are unrelated to the direction of gravity.

[0010] The first insulating portion 21 is provided below the first electrode 11. The second electrode 12 is provided below the first insulating portion 21. That is, the first insulating portion 21 is provided between the first electrode 11 and the second electrode 12 in the Z direction. This allows the first electrode 11 and the second electrode 12 to be electrically isolated from each other. The first electrode 11 and the second electrode 12 face each other in the Z direction. At least a portion of the second electrode 12 overlaps with at least a portion of the first electrode 11 in the Z direction.

[0011] The second insulating portion 22 is provided around the first electrode 11 along an XY plane (first surface) perpendicular to the Z direction. The third insulating portion 23 is provided around the second electrode 12 along an XY plane (second surface) perpendicular to the Z direction.

[0012] The first dielectric portion 31 is provided between the first electrode 11 and the second insulating portion 22 in the X direction and the Y direction. The first dielectric portion 31 is in contact with the first electrode 11. The relative dielectric constant of the first dielectric portion 31 is higher than the relative dielectric constant of the first insulating portion 21.

[0013] The second dielectric portion 32 is provided between the second electrode 12 and the third insulating portion 23 in the X direction and the Y direction. The second dielectric portion 32 is in contact with the second electrode 12. The second dielectric portion 32 has a higher dielectric constant than the first insulating portion 21.

[0014] In this example, the first electrode 11 and the second electrode 12 are coils arranged in a spiral shape along the XY plane. That is, the digital isolator 100 is a magnetically coupled digital isolator. The first electrode 11 and the second electrode 12 may be flat electrodes along the XY plane. That is, the digital isolator 100 may be a capacitively coupled digital isolator.

[0015] A first intermediate dielectric portion 33 is provided along the XY plane between the coils of the first electrode 11. The relative dielectric constant of the first intermediate dielectric portion 33 is higher than the relative dielectric constant of the first insulating portion 21. A second intermediate dielectric portion 34 is provided along the XY plane between the coils of the second electrode 12. The relative dielectric constant of the second intermediate dielectric portion 34 is higher than the relative dielectric constant of the first insulating portion 21.

[0016] The insulating layer 41 is provided on the first electrode 11. The insulating layer 41 is provided between the first electrode 11 and the upper insulating portion 28 in the Z direction. The insulating layer 41 is in contact with the first electrode 11, for example. The insulating layer 42 is provided below the first electrode 11. The insulating layer 42 is provided between the first electrode 11 and the first insulating portion 21 in the Z direction. The insulating layer 42 is in contact with the first electrode 11, for example. The insulating layer 43 is provided on the second electrode 12. The insulating layer 43 is provided between the second electrode 12 and the first insulating portion 21 in the Z direction. The insulating layer 43 is in contact with the second electrode 12, for example.

[0017] The conductor 50 is provided at a position away from the first electrode 11 and the second electrode 12 in the X direction. The conductor 50 is provided, for example, around the first electrode 11 and the second electrode 12 along the first surface. In this example, the conductor 50 includes a first conductive portion 51, a second conductive portion 52, and a third conductive portion 53.

[0018] The first conductive portion 51 is provided at a position away from the first electrode 11 in the X direction. The second insulating portion 22 and the first dielectric portion 31 are located between the first conductive portion 51 and the first electrode 11 in the X direction. The second insulating portion 22 is in contact with the first conductive portion 51. The second conductive portion 52 is provided below the first conductive portion 51. The first insulating portion 21 is in contact with the second conductive portion 52. The third conductive portion 53 is provided below the second conductive portion 52. The third conductive portion 53 is provided at a position away from the second electrode 12 in the X direction. The third insulating portion 23 and the second dielectric portion 32 are located between the third conductive portion 53 and the second electrode 12 in the X direction. The third insulating portion 23 is in contact with the third conductive portion 53.

[0019] A portion of the insulating layer 41 is provided on the first conductive portion 51. A portion of the insulating layer 41 is in contact with, for example, the first conductive portion 51. A portion of the insulating layer 42 is provided around the bottom of the first conductive portion 51 along the XY plane. A portion of the insulating layer 42 is in contact with, for example, the first conductive portion 51. A portion of the insulating layer 43 is provided around the bottom of the second conductive portion 52 along the XY plane. A portion of the insulating layer 43 is in contact with, for example, the second conductive portion 52 and the third conductive portion 53.

[0020] Both ends of the first electrode 11 (both ends of the coil) are electrically connected to a first circuit (not shown) via wiring, and both ends of the second electrode 12 (both ends of the coil) are electrically connected to a second circuit (not shown) via wiring.

[0021] In this example, the second electrode 12 is electrically connected to the second circuit via the conductor 50. That is, in this example, the conductor 50 functions as an electrode for drawing the wiring of the second electrode 12 upward. The second electrode 12 is electrically connected to the conductor 50, for example, via a third conductive portion 53. The conductor 50 is electrically connected to the second circuit, for example, via a connection portion 60 that contacts the first conductive portion 51 above the first conductive portion 51. Note that the conductor 50 does not have to be electrically connected to the second electrode 12. The conductor 50 may be, for example, an electrode or a circuit of a component adjacent to the digital isolator 100.

[0022] An upper insulating portion 28 is provided on the first electrode 11 and the conductor 50. More specifically, the upper insulating portion 28 is provided on the first electrode 11, the first intermediate dielectric portion 33, the first dielectric portion 31, the second insulating portion 22, and the first conductive portion 51. The connection portion 60 is provided inside the upper insulating portion 28.

[0023] One of the first circuit and the second circuit is used as a transmitting circuit. The other of the first circuit and the second circuit is used as a receiving circuit. Here, a case will be described in which the first circuit is a transmitting circuit and the second circuit is a receiving circuit.

[0024] The first circuit sends a signal (current) with a waveform suitable for transmission to the first electrode 11. When the current flows through the first electrode 11, a magnetic field is generated that passes through the inside of the spiral first electrode 11. At least a part of the first electrode 11 is aligned with at least a part of the second electrode 12 in the Z direction. A part of the generated magnetic field lines passes through the inside of the second electrode 12. Due to a change in the magnetic field inside the second electrode 12, an induced electromotive force is generated in the second electrode 12, and a current flows through the second electrode 12. The second circuit detects the current flowing through the second electrode 12 and generates a signal according to the detection result. As a result, a signal or energy is transmitted between the first electrode 11 and the second electrode 12 while the current is blocked (insulated).

[0025] An example of the material of each component of the digital isolator 100 will be described. The first electrode 11, the second electrode 12, and the conductor 50 each contain, for example, a metal. The first electrode 11, the second electrode 12, and the conductor 50 each contain, for example, at least one metal selected from the group consisting of copper and aluminum.

[0026] The first insulating portion 21, the second insulating portion 22, the third insulating portion 23, and the upper insulating portion 28 contain silicon and oxygen. The first insulating portion 21, the second insulating portion 22, the third insulating portion 23, and the upper insulating portion 28 contain, for example, silicon oxide. The first insulating portion 21, the second insulating portion 22, the third insulating portion 23, and the upper insulating portion 28 may further contain carbon or nitrogen.

[0027] The insulating layers 41 to 43 contain silicon and nitrogen. The insulating layers 41 to 43 contain, for example, silicon nitride. The insulating layers 41 to 43 may further contain carbon.

[0028] The first dielectric portion 31, the second dielectric portion 32, the first intermediate dielectric portion 33, and the second intermediate dielectric portion 34 include, for example, silicon and nitrogen. The first dielectric portion 31, the second dielectric portion 32, the first intermediate dielectric portion 33, and the second intermediate dielectric portion 34 include, for example, silicon nitride. The first dielectric portion 31, the second dielectric portion 32, the first intermediate dielectric portion 33, and the second intermediate dielectric portion 34 may further include carbon.

[0029] The relative dielectric constant of the first dielectric portion 31 is higher than the relative dielectric constant of the first insulating portion 21. The relative dielectric constant of the first dielectric portion 31 is, for example, higher than the relative dielectric constant of the second insulating portion 22. The relative dielectric constant of the second dielectric portion 32 is higher than the relative dielectric constant of the first insulating portion 21. The relative dielectric constant of the second dielectric portion 32 is, for example, higher than the relative dielectric constant of the third insulating portion 23. The relative dielectric constant of the first dielectric portion 31 and the relative dielectric constant of the second dielectric portion 32 are, for example, the same. The relative dielectric constant of the first dielectric portion 31 and the relative dielectric constant of the second dielectric portion 32 may be different.

[0030] The relative dielectric constant of the first intermediate dielectric portion 33 is higher than the relative dielectric constant of the first insulating portion 21. The relative dielectric constant of the first intermediate dielectric portion 33 and the relative dielectric constant of the first dielectric portion 31 are, for example, the same. The relative dielectric constant of the first intermediate dielectric portion 33 and the relative dielectric constant of the first dielectric portion 31 may be different. The relative dielectric constant of the second intermediate dielectric portion 34 is higher than the relative dielectric constant of the first insulating portion 21. The relative dielectric constant of the second intermediate dielectric portion 34 and the relative dielectric constant of the second dielectric portion 32 are, for example, the same. The relative dielectric constant of the second intermediate dielectric portion 34 and the relative dielectric constant of the second dielectric portion 32 may be different. The relative dielectric constant of the first intermediate dielectric portion 33 and the relative dielectric constant of the second intermediate dielectric portion 34 are, for example, the same. The relative dielectric constant of the first intermediate dielectric portion 33 and the relative dielectric constant of the second intermediate dielectric portion 34 may be different.

[0031] The X-direction width W1 of the second insulating portion 22 is, for example, larger than the X-direction width W2 of the first dielectric portion 31. The width W2 is, for example, smaller than half the X-direction distance between the first electrode 11 and the conductor 50 (first conductive portion 51). The X-direction width W3 of the third insulating portion 23 is, for example, larger than the X-direction width W4 of the second dielectric portion 32. The width W4 is, for example, smaller than half the X-direction distance between the second electrode 12 and the conductor 50 (third conductive portion 53). The width W2 and the width W4 are, for example, the same. The width W2 and the width W4 may be different.

[0032] The Z-direction thickness T1 of the first dielectric portion 31 is, for example, the same as the Z-direction thickness T2 of the first electrode 11. The thickness T1 is, for example, the same as the Z-direction thickness T3 of the second insulating portion 22. The thickness T1 is, for example, the same as the Z-direction thickness T4 of the first intermediate dielectric portion 33. The Z-direction thickness T5 of the second dielectric portion 32 is, for example, the same as the Z-direction thickness T6 of the second electrode 12. The thickness T5 is, for example, the same as the Z-direction thickness T7 of the third insulating portion 23. The thickness T5 is, for example, the same as the Z-direction thickness T8 of the second intermediate dielectric portion 34.

[0033] The effects of the first embodiment will be described below. When a signal is transmitted between the first electrode 11 and the second electrode 12, a potential difference occurs between the first electrode 11 and the second electrode 12. This may cause electric field concentration near the lower end of the first electrode 11 and near the upper end of the second electrode 12, which may lead to dielectric breakdown. In addition, the driving voltage of the first circuit and the second circuit, the potential difference between the first circuit and the second circuit, and unexpected high voltages and surges occurring in the first circuit and / or the second circuit may also cause electric field concentration near the lower end of the first electrode 11 and near the upper end of the second electrode 12, which may lead to dielectric breakdown.

[0034] One possible means for increasing the dielectric breakdown resistance is, for example, increasing the thickness in the Z direction of first insulating section 21. However, increasing the thickness in the Z direction of first insulating section 21 may increase warping of a substrate (e.g., a wafer) on which a digital isolator is formed in the manufacturing process, and may increase manufacturing costs.

[0035] In contrast, in the digital isolator 100 according to the first embodiment, a first dielectric portion 31 having a higher dielectric constant than the first insulating portion 21 is provided at a position adjacent to the first electrode 11, so that the electric field lines between the first electrode 11 and the second electrode 12 can be drawn to the first dielectric portion 31 side. This makes it possible to alleviate the electric field concentration in the vicinity of the lower end of the first electrode 11 and improve the dielectric breakdown resistance without increasing the thickness of the first insulating portion 21 in the Z direction.

[0036] Furthermore, by providing both the second insulating portion 22 and the first dielectric portion 31 between the first electrode 11 and the conductor 50, the second insulating portion 22 having excellent voltage resistance can improve dielectric breakdown resistance compared to, for example, a case in which the entire area between the first electrode 11 and the conductor 50 is the first dielectric portion 31. Furthermore, by making the width W1 in the X direction of the second insulating portion 22 larger than the width W2 in the X direction of the first dielectric portion 31, the second insulating portion 22 having excellent voltage resistance can further improve dielectric breakdown resistance.

[0037] Furthermore, by providing a first intermediate dielectric portion 33 having a higher dielectric constant than the first insulating portion 21 between the coils of the first electrode 11, the electric field lines between the first electrode 11 and the second electrode 12 can be drawn toward the first intermediate dielectric portion 33. This can further alleviate the electric field concentration in the vicinity of the lower end of the first electrode 11, and further improve the dielectric breakdown resistance.

[0038] Similarly, by providing a second dielectric portion 32 having a higher relative dielectric constant than the first insulating portion 21 at a position adjacent to the second electrode 12, the electric field lines between the first electrode 11 and the second electrode 12 can be drawn toward the second dielectric portion 32. This makes it possible to alleviate the electric field concentration in the vicinity of the upper end of the second electrode 12 and improve the dielectric breakdown resistance without increasing the thickness of the first insulating portion 21 in the Z direction.

[0039] Furthermore, by providing both the third insulating portion 23 and the second dielectric portion 32 between the second electrode 12 and the conductor 50, the dielectric breakdown resistance can be improved by the third insulating portion 23 having excellent voltage resistance, compared to, for example, a case in which the entire area between the second electrode 12 and the conductor 50 is the second dielectric portion 32. Furthermore, by making the X-direction width W3 of the third insulating portion 23 larger than the X-direction width W4 of the second dielectric portion 32, the dielectric breakdown resistance can be further improved by the third insulating portion 23 having excellent voltage resistance.

[0040] Furthermore, by providing a second intermediate dielectric portion 34 having a higher dielectric constant than the first insulating portion 21 between the coils of the second electrode 12, the electric field lines between the first electrode 11 and the second electrode 12 can be drawn toward the second intermediate dielectric portion 34. This can further alleviate the electric field concentration in the vicinity of the upper end of the second electrode 12, and further improve the dielectric breakdown resistance.

[0041] Second embodiment FIG. 2 is a cross-sectional view illustrating a digital isolator according to the second embodiment. As shown in FIG. 2, the digital isolator 200 according to the second embodiment includes a first electrode 11, a second electrode 12, a first insulating section 21, a second insulating section 22, a third insulating section 23, an upper insulating section 28, a first dielectric layer 36, a second dielectric layer 37, insulating layers 41 to 43, and a conductor 50.

[0042] The digital isolator 200 according to the second embodiment is the same as the digital isolator 100 according to the first embodiment, except that the first dielectric portion 31, the second dielectric portion 32, the first intermediate dielectric portion 33, and the second intermediate dielectric portion 34 are not provided, and a first dielectric layer 36 and a second dielectric layer 37 are provided. Descriptions of the same configurations will be omitted.

[0043] A second insulating portion 22 is provided over the entire area between the first electrode 11 and the conductor 50. In addition, a second insulating portion 22 is also provided between the coils of the first electrode 11. A third insulating portion 23 is provided over the entire area between the second electrode 12 and the conductor 50. In addition, a third insulating portion 23 is also provided between the coils of the second electrode 12.

[0044] The first dielectric layer 36 and the second dielectric layer 37 are each provided inside the upper insulating portion 28. The first dielectric layer 36 is located on one of the first electrode 11 and the conductor 50. The second dielectric layer 37 is located on the other of the first electrode 11 and the conductor 50. In this example, the first dielectric layer 36 is provided on the first electrode 11, and the second dielectric layer 37 is provided on the conductor 50.

[0045] The first dielectric layer 36 and the second dielectric layer 37 include, for example, silicon and nitrogen. The first dielectric layer 36 and the second dielectric layer 37 include, for example, silicon nitride. The first dielectric layer 36 and the second dielectric layer 37 may further include carbon.

[0046] The relative dielectric constant of the first dielectric layer 36 is higher than that of the second insulating portion 22. The relative dielectric constant of the first dielectric layer 36 is higher than that of the upper insulating portion 28, for example. The relative dielectric constant of the second dielectric layer 37 is higher than that of the second insulating portion 22. The relative dielectric constant of the second dielectric layer 37 is higher than that of the upper insulating portion 28, for example. The relative dielectric constant of the first dielectric layer 36 and the relative dielectric constant of the second dielectric layer 37 are, for example, the same. The relative dielectric constant of the first dielectric layer 36 and the relative dielectric constant of the second dielectric layer 37 may be different.

[0047] The width W11 in the X direction of the first dielectric layer 36 is, for example, the same as the width W13 in the X direction of the coil portion of the first electrode 11. The width W11 may be, for example, larger than the width W13. The width W12 in the X direction of the second dielectric layer 37 is, for example, the same as the width W14 in the X direction of the first conductive portion 51. The width W12 may be, for example, larger than the width W14.

[0048] The thickness T11 in the Z direction of the first dielectric layer 36 is, for example, equal to or smaller than the thickness T13 in the Z direction of the upper insulating portion 28. The thickness T11 is, for example, approximately the same as the thickness T2 in the Z direction of the first electrode 11. The thickness T11 may be greater than or smaller than the thickness T2. The thickness T12 in the Z direction of the second dielectric layer 37 is, for example, equal to or smaller than the thickness T13. The thickness T12 is, for example, approximately the same as the thickness T2. The thickness T12 may be greater than or smaller than the thickness T2.

[0049] The effects of the second embodiment will be described below. In the case where the conductor 50 is provided in the vicinity of the first electrode 11 and the second electrode 12, a potential difference occurs between the first electrode 11 and the conductor 50 when a signal is transmitted between the first electrode 11 and the second electrode 12. This may cause electric field concentration near the side end of the first electrode 11 and the side end of the conductor 50, which may lead to dielectric breakdown. In addition, the driving voltage of the first circuit and the second circuit, the potential difference between the first circuit and the second circuit, and unexpected high voltages and surges occurring in the first circuit and / or the second circuit may also cause electric field concentration near the side end of the first electrode 11 and the side end of the conductor 50, which may lead to dielectric breakdown.

[0050] One possible means for increasing the dielectric breakdown resistance is to increase the distance between the first electrode 11 and the conductor 50. However, increasing the distance between the first electrode 11 and the conductor 50 may increase the chip area, which in turn increases the manufacturing cost.

[0051] In contrast, in the digital isolator 200 according to the second embodiment, a first dielectric layer 36 having a higher dielectric constant than the second insulating section 22 is provided on one of the first electrode 11 and the conductor 50, so that the electric field lines between the first electrode 11 and the conductor 50 can be drawn to the first dielectric layer 36 side. This makes it possible to alleviate electric field concentration in the vicinity of one side end of the first electrode 11 and the conductor 50, and improve dielectric breakdown resistance without increasing the chip area.

[0052] Similarly, by providing a second dielectric layer 37 having a higher dielectric constant than the second insulating section 22 on the other of the first electrode 11 and the conductor 50, the electric field lines between the first electrode 11 and the conductor 50 can be drawn to the second dielectric layer 37 side. This makes it possible to alleviate electric field concentration in the vicinity of the other side ends of the first electrode 11 and the conductor 50, and improve dielectric breakdown resistance without increasing the chip area.

[0053] In addition, if the conductor 50 and the second electrode 12 are not electrically connected, a potential difference may occur between the second electrode 12 and the conductor 50. In this case, for example, a dielectric layer may be provided below the second electrode 12 and below the third conductive portion 53. When these dielectric layers are provided, the relative dielectric constants of these dielectric layers are set higher than the relative dielectric constant of the third insulating portion 23. This can alleviate the electric field concentration between the second electrode 12 and the conductor 50, as in the case where the above-mentioned first dielectric layer 36 and second dielectric layer 37 are provided, and can improve the dielectric breakdown resistance without increasing the chip area.

[0054] Third embodiment FIG. 3 is a cross-sectional view illustrating a digital isolator according to the third embodiment. As shown in FIG. 3, the digital isolator 300 of the third embodiment includes a first electrode 11, a second electrode 12, a first insulating section 21, a second insulating section 22, a third insulating section 23, an upper insulating section 28, a first dielectric section 31, a second dielectric section 32, a first intermediate dielectric section 33, a second intermediate dielectric section 34, a first dielectric layer 36, a second dielectric layer 37, insulating layers 41 to 43, and a conductor 50.

[0055] In the digital isolator 300 according to the third embodiment, in addition to the first dielectric portion 31, the second dielectric portion 32, the first intermediate dielectric portion 33, and the second intermediate dielectric portion 34 of the digital isolator 100 according to the first embodiment, the first dielectric layer 36 and the second dielectric layer 37 of the digital isolator 200 according to the second embodiment are provided. The configuration of each portion is the same as in the first and second embodiments, so a description thereof will be omitted.

[0056] In the digital isolator 300 of the third embodiment, by providing the first dielectric portion 31, the second dielectric portion 32, the first intermediate dielectric portion 33, and the second intermediate dielectric portion 34, it is possible to alleviate electric field concentration near the lower end of the first electrode 11 and near the upper end of the second electrode 12, and improve the dielectric breakdown resistance without increasing the thickness of the first insulating portion 21 in the Z direction.

[0057] Furthermore, in the digital isolator 300 of the third embodiment, by providing the first dielectric layer 36 and the second dielectric layer 37, electric field concentration near the side ends of the first electrode 11 and the conductor 50 can be alleviated, and the dielectric breakdown resistance can be improved without increasing the chip area.

[0058] As described above, according to the embodiment, a digital isolator capable of improving dielectric breakdown resistance is provided.

[0059] Although some embodiments of the present invention have been illustrated above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. In addition, the above-mentioned embodiments can be implemented in combination with each other. [Explanation of symbols]

[0060] 11 first electrode, 12 second electrode, 21 first insulating portion, 22 second insulating portion, 23 third insulating portion, 28 upper insulating portion, 31 first dielectric portion, 32 second dielectric portion, 33 first intermediate dielectric portion, 34 second intermediate dielectric portion, 36 first dielectric layer, 37 second dielectric layer, 41 to 43 insulating layer, 50 conductor, 51 first conductive portion, 52 second conductive portion, 53 third conductive portion, 60 connection portion, 100, 200, 300 digital isolator

Claims

1. A first electrode; a first insulating portion provided under the first electrode; a second electrode provided under the first insulating portion; a second insulating portion provided around the first electrode along a first surface perpendicular to a first direction from the second electrode toward the first electrode; a first dielectric portion provided between the first electrode and the second insulating portion in a second direction along the first surface and in contact with the first electrode; Equipped with the first dielectric portion has a higher dielectric constant than the first insulating portion; the first electrode is located between a first insulating layer containing silicon and nitrogen and a second insulating layer containing silicon and nitrogen in the first direction; A digital isolator, wherein the first insulating portion is located between the second insulating layer and a third insulating layer containing silicon and nitrogen in the first direction.

2. The digital isolator according to claim 1 , wherein the width of the second insulating portion in the second direction is larger than the width of the first dielectric portion in the second direction.

3. the first electrode is a coil provided in a spiral shape along the first surface, a first intermediate dielectric portion disposed between the coils along the first surface; The digital isolator according to claim 1 , wherein the first intermediate dielectric portion has a higher dielectric constant than the first insulating portion.

4. a third insulating portion provided around the second electrode along a second surface perpendicular to the first direction; a second dielectric portion provided between the second electrode and the third insulating portion in the second direction and in contact with the second electrode; Further equipped with 4. The digital isolator according to claim 1, wherein the second dielectric portion has a higher dielectric constant than the first insulating portion.

5. The digital isolator according to claim 4 , wherein the width of the third insulating portion in the second direction is larger than the width of the second dielectric portion in the second direction.

6. the second electrode is a coil provided in a spiral shape along the second surface, a second intermediate dielectric portion disposed between the coils along the second surface; The digital isolator according to claim 4 , wherein the second intermediate dielectric portion has a higher dielectric constant than the first insulating portion.

7. A first electrode; a first insulating portion provided under the first electrode; a second electrode provided under the first insulating portion; a conductor provided at a position away from the first electrode in a second direction perpendicular to a first direction from the second electrode toward the first electrode; a second insulating portion provided between the first electrode and the conductor in the second direction; an upper insulating portion provided on the first electrode and the conductor; a first dielectric layer disposed within the upper insulating portion and overlying one of the first electrode and the conductor; Equipped with the first dielectric layer has a higher dielectric constant than the second insulating portion; a thickness of the first dielectric layer is greater than or equal to a thickness of the first electrode; the first electrode is located between a first insulating layer containing silicon and nitrogen and a second insulating layer containing silicon and nitrogen in the first direction; A digital isolator, wherein the first insulating portion is located between the second insulating layer and a third insulating layer containing silicon and nitrogen in the first direction.

8. a second dielectric layer provided within the upper insulating portion and positioned on the other of the first electrode and the conductor; The digital isolator according to claim 7 , wherein the second dielectric layer has a higher dielectric constant than the second insulating portion.

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